The present application claims priority under 35 U.S.C. xc2xa7119 to Japanese Patent Application No. 2001-325559, filed on Oct. 23, 2001, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a rear wheel suspension device for a saddle ride vehicle, for example, a vehicle for running on rough terrain.
2. Description of Background Art
Heretofore, a saddle ride vehicle such as the structure shown in FIG. 6 has been known.
The saddle ride vehicle denoted by numeral 1 in the figure comprises a vehicle body frame 2, front wheels 3 fitted on both sides of a front lower portion of the vehicle body frame 2, and rear wheels 4 fitted on both sides of a rear lower portion of the vehicle body frame 2. The rear wheels 4 are each vertically movably supported by a rear wheel suspension device which comprises a swing arm 5 vertically oscillatably fitted to a rear lower portion of the vehicle body frame 2, and a shock absorber 6 intermediately provided between an oscillation end portion of the swing arm 5 and the vehicle body frame 2 located on the upper side of the oscillation end portion.
In addition, a fender 7 is provided covering the upper side of the vehicle body frame 2, the front wheels 3, and the rear wheels 4, and a seat 8 for the rider W is provided at a roughly central portion of the vehicle body frame 2.
In addition, Japanese Patent Publication No. Hei 7-90818 shows an example of a support structure for the rear wheels 4, in which the suspension device is a so-called diagonal suspension.
In the saddle ride vehicle 1 comprising such swing arms 5 according to the related art, there is still the following problem left to be improved. Namely, when the rear wheel 4 is moved vertically, the rear wheel 4 is moved along an arc-shaped movement locus around the oscillation center of the swing arm 5, so that the rear wheel 4 is moved skewly forwards.
Where the stroke of the vertical movement of the rear wheel 4 must be enlarged, it is necessary to shift the fender 7 forwards for securing a space for movement of the rear wheel 4. With the fender 7 thus shifted forwards, however, it becomes necessary to shift also a rear end portion of the seat 8 forwards. As a result, there is the problem that a riding space for the rider W is narrowed.
Besides, in the rear wheel suspension device using the above-mentioned diagonal suspension, the movement locus of the rear wheel is roughly linear, and the forward movement of the vehicle is reduced. However, depending on the stroke amount of the rear wheels, the above-mentioned problem is again generated.
The present invention has been made in consideration of the above problem in the related art. Accordingly, it is an object of the present invention to provide a rear wheel suspension device for saddle ride vehicle which does not influence the riding space for the rider even where the stroke of rear wheels is enlarged.
In order to attain the above object, according to a first aspect of the present invention, a rear wheel suspension device for saddle ride vehicle fits a pair of left and right rear wheels to a vehicle body frame, and includes a suspension arm which is vertically oscillatably fitted to the vehicle body frame and is fitted with an axle of the rear wheel at an oscillation end portion thereof. In this configuration, the oscillation axis of the suspension arm is inclined so as to be higher on the front side than on the rear side of the saddle ride vehicle.
According to a second aspect of the present invention, first and second suspension arms are provided at vertically spaced two positions, and the oscillation axes of the suspension arms are set substantially parallel to each other.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.